Alpha particles are most commonly used in smoke alarms.These alarms contain a tiny amount of decaying Americium between two sheets of metal. A small electric current is then passed through one of the sheets and into the second one.Even with such intense barriers, some radiation may still get through because of how small the rays are.
They are still viewed as the least dangerous form of radiation, as long as it's not ingested or inhaled, because it can be stopped by even a thin sheet of paper or even skin, meaning that it cannot enter the body very easily.
A case of alpha radiation poisoning made international news a few years ago when Russian dissident Alexander Litvinenko was believed to have been poisoned with it by the Russian spy service.
They are emitted by a decaying nucleus, that expels the gamma rays in an effort to become more stable as an atom.
Gamma rays have the most energy and can penetrate substances up to a few centimetres of lead or a few metres of concrete.
All living cells take up carbon-14, whether from photosynthesis or eating other living cells.